The adoption of photovoltaics for generating electricity from sunlight is largely driven by cost considerations. At present, photovoltaic systems are not competitive with fossil-fuel generated electricity. Thus, there is a need to reduce the overall photovoltaic system cost. This entails reducing the cost of photovoltaic modules as well as module assembly costs with enhanced functionality.
One way to reduce costs is to reduce the size of the photovoltaic solar cells. In this aspect, small and thin photovoltaic cells have been developed that reduce photovoltaic material use dramatically. These thin photovoltaic cells are typically formed on top of a handle wafer. Once formed, the cells may be individually detached from the handle wafer by, for example, an etching process using a hydrofluoric acid (HF) solution to undercut the cells. These “free floating” cells may then be assembled into sheets by attracting the individual cells to a desired position on a sheet of material using self-assembly techniques. Finally, the cells may be embedded in a low-cost substrate with contacts and microlenses to form photovoltaic sheets.